/*
 * Copyright (c) 2007 T.Cogghe, D.Leroux, S.Lévignac, S.Rives
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#ifndef __ID_H__
#define __ID_H__

/* classe de base pour les identités */



/* _tol est un pourcentage de tolérance pour == et != */
class Id {
	double _tol;

public:
	Id(double _t) : _tol(_t) {}
	virtual ~Id() {}

	/* comparer deux identités (prédicat "ressemble à") */
	virtual bool operator == (const Id&i) const { return 0; }

	bool operator != (const Id&i) const {
		return !((*this)==i);
	}

	static double deltaPourcents(double a,double b) {
		//cout<<"deltaPourcents("<<a<<','<<b<<')'<<endl;
		if(a==b) {
			return 0;
		}
		if(a>b) {
			if(b==0) return a;
			return (a-b)/b;
		}
		if(a==0) {
			return b;
		}
		return (b-a)/a;
	}

	/* estimer l'éloignement entre deux identités */
	virtual double operator % (const Id&i) const {
		return 0;
	}
};


#endif
